Repeated Internal Program Error - 30636.k.no.ts - Xara Pro+v21.2

[Acorn]

Dear Xara...

With Xara Designer Pro+ 21.2.0.62177 M SL x64 May 18 2021, when I try anything half-complex, like deleting more than two objects, shared across Variants, I get this pop-up:



It then recurs after every letter typed or object change.

I can save, close and re-open and continue working for a period and then back it comes.

Can we have a Patch for the Patch?

I have Run as admin.
I have cold-started my machine.
I get it across my last 37 design files.

As ever, note to self - never trust a Xara update in the middle of a project!

Acorn

P.S. The Patch did not fix a number of my still Templates being forced back into Exporting WebP despite being saved as unticked.
I have to untick all my designs on re-opening.
I have no problem with WebP but I have this project where the client is still on v16 and has no need for it at the moment.
The downside I have is an Export Website can hang or take a very long time for the first export of the day! Thereafter, subsequent session exports are only two to three time longer with WebP than without. Only.